package com.hmdp.service.impl;

import cn.hutool.core.bean.BeanUtil;
import com.hmdp.dto.Result;
import com.hmdp.entity.SeckillVoucher;
import com.hmdp.entity.VoucherOrder;
import com.hmdp.mapper.VoucherOrderMapper;
import com.hmdp.service.ISeckillVoucherService;
import com.hmdp.service.IVoucherOrderService;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.hmdp.utils.RedisIdWorker;
import com.hmdp.utils.SimpleRedisLock;
import com.hmdp.utils.UserHolder;
import lombok.extern.slf4j.Slf4j;
import org.redisson.api.RLock;
import org.redisson.api.RedissonClient;
import org.springframework.aop.framework.AopContext;
import org.springframework.core.io.ClassPathResource;
import org.springframework.data.redis.connection.stream.*;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.data.redis.core.script.DefaultRedisScript;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import javax.annotation.PostConstruct;
import javax.annotation.Resource;
import java.time.Duration;
import java.time.LocalDateTime;
import java.util.Collections;
import java.util.List;
import java.util.Map;
import java.util.concurrent.*;

/**
 * <p>
 *  服务实现类
 * </p>
 *
 * @author 虎哥
 * @since 2021-12-22
 */
@Service
@Slf4j
public class VoucherOrderServiceImpl extends ServiceImpl<VoucherOrderMapper, VoucherOrder> implements IVoucherOrderService {

    @Resource
    private ISeckillVoucherService seckillVoucherService;
    @Resource
    private RedisIdWorker redisIdWorker;
    @Resource
    private StringRedisTemplate stringRedisTemplate;
    @Resource
    private RedissonClient redissonClient;

    private static final DefaultRedisScript<Long> SECKILL_SCRIPT;

    static {
        SECKILL_SCRIPT = new DefaultRedisScript<>();
        SECKILL_SCRIPT.setLocation(new ClassPathResource("seckill.lua"));
        SECKILL_SCRIPT.setResultType(Long.class);
    }
    //创建redis消息队列
//    private BlockingQueue<VoucherOrder> orderTasks = new ArrayBlockingQueue<>(1024*1024);
    //创建线程池
    private static final ExecutorService SECKILL_ORDER_EXECUTOR = Executors.newSingleThreadExecutor();
    @PostConstruct
    private void init() {
        SECKILL_ORDER_EXECUTOR.submit(new VoucherOrderHandler());
    }
    //任务类
    private class VoucherOrderHandler implements Runnable {
        String queueName= "stream.orders";
        @Override
        public void run() {
            while(true) {
                try {
                    //获取消息队列中的信息
                    List<MapRecord<String, Object, Object>> list = stringRedisTemplate.opsForStream().read(
                            Consumer.from("g1", "c1"), // 消费组信息
                            StreamReadOptions.empty().count(1).block(Duration.ofSeconds(2)),
                            StreamOffset.create(queueName, ReadOffset.lastConsumed())

                    );
                    //判断消息获取是否成功
                    if(list==null || list.isEmpty()) {
                        //1.如果获取失败，说明没有消息 循环等待
                        break;
                    }
                    MapRecord<String, Object, Object> record = list.get(0);
                    Map<Object, Object> values = record.getValue();
                    VoucherOrder voucherOrder = BeanUtil.fillBeanWithMap(values, new VoucherOrder(), true);
                    //2.如果获取成功，开始下单
                    handleVoucherOrder(voucherOrder);
                    //3.ack确认
                    stringRedisTemplate.opsForStream().acknowledge(queueName,"g1",record.getId());
                } catch (Exception e) {
                    log.info("订单信息获取失败",e);
                    handlePendingList();
                }
            }

        }

        private void handlePendingList() {
            while(true) {
                try {
                    //获取pendinglist中的信息
                    List<MapRecord<String, Object, Object>> list = stringRedisTemplate.opsForStream().read(
                            Consumer.from("g1", "c1"),
                            StreamReadOptions.empty().count(1),
                            StreamOffset.create(queueName, ReadOffset.from("0"))

                    );
                    //判断pendinglist获取是否成功
                    if(list==null || list.isEmpty()) {
                        //1.如果获取失败，说明没有消息 结束循环
                        break;
                    }
                    MapRecord<String, Object, Object> record = list.get(0);
                    Map<Object, Object> values = record.getValue();
                    VoucherOrder voucherOrder = BeanUtil.fillBeanWithMap(values, new VoucherOrder(), true);
                    //2.如果获取成功，开始下单
                    handleVoucherOrder(voucherOrder);
                    //3.ack确认
                    stringRedisTemplate.opsForStream().acknowledge(queueName,"g1",record.getId());
                } catch (Exception e) {
                    log.info("订单信息获取失败",e);
                    try {
                        Thread.sleep(20);
                    } catch (InterruptedException ex) {
                        ex.printStackTrace();
                    }
                }
            }

        }
    }
//    private class VoucherOrderHandler implements Runnable {
//
//        @Override
//        public void run() {
//            while(true) {
//                try {
//                    //获取队列中的信息
//                    VoucherOrder take = orderTasks.take();
//                    //创建订单
//                    handleVoucherOrder(take);
//                } catch (InterruptedException e) {
//                    log.info("订单信息获取失败",e);
//                }
//            }
//
//        }
//    }
    private void handleVoucherOrder(VoucherOrder voucherOrder) {
        //获取用户
        Long userId = voucherOrder.getUserId();
        //创建锁对象
        String name = "lock:order:" + userId;
//        SimpleRedisLock simpleRedisLock = new SimpleRedisLock(name, stringRedisTemplate);
        RLock lock = redissonClient.getLock(name);
        //获取锁
        boolean b = lock.tryLock();
        //判断获取锁是否成功
        if (!b) {
            //获取锁失败，直接返回失败或者重试
            log.info("不能重复下单");
            return;

        }
        try {

            proxy.createVoucherOrder(voucherOrder); //先提交事务
        } finally {
            lock.unlock();
        }
    }

    private IVoucherOrderService proxy;
    @Override
    public Result seckillVoucher(Long voucherId) {
        //1.查询优惠券信息
        SeckillVoucher byId = seckillVoucherService.getById(voucherId);
        //获取订单id
        Long orderId = redisIdWorker.nextId("order");
        //2.判断优惠券是否开放以及是否结束
        if (byId.getBeginTime().isAfter(LocalDateTime.now())
                || byId.getEndTime().isBefore(LocalDateTime.now())) {
            return Result.fail("优惠券尚未开始或已经结束");
        }
        Long userId = UserHolder.getUser().getId();
        //1.执行lua脚本
        Long execute = stringRedisTemplate.execute(
                SECKILL_SCRIPT,
                Collections.emptyList(),
                voucherId.toString(),
                userId.toString(),
                String.valueOf(orderId)
        );
        //2.判断结果是否为零
        int i = execute.intValue();
        if (i != 0) {
            return Result.fail(i == 1 ? "库存不足" : "不能重复下单");
        }
        //获取代理对象
        proxy = (IVoucherOrderService) AopContext.currentProxy();
        //3.返回订单id
        return Result.ok(orderId);
    }


//    @Override
//    public Result seckillVoucher(Long voucherId) {
//        //1.查询优惠券信息
//        SeckillVoucher byId = seckillVoucherService.getById(voucherId);
//        //2.判断优惠券是否开放以及是否结束
//        if (byId.getBeginTime().isAfter(LocalDateTime.now())
//                || byId.getEndTime().isBefore(LocalDateTime.now())) {
//            return Result.fail("优惠券尚未开始或已经结束");
//        }
//        Long userId = UserHolder.getUser().getId();
//        //1.执行lua脚本
//        Long execute = stringRedisTemplate.execute(
//                SECKILL_SCRIPT,
//                Collections.emptyList(),
//                voucherId.toString(),
//                userId.toString()
//        );
//        //2.判断结果是否为零
//        int i = execute.intValue();
//        if (i != 0) {
//            return Result.fail(i == 1 ? "库存不足" : "不能重复下单");
//        }
//        //2。2.结果为零 将下单信息保存到阻塞队列中
//        Long orderId = redisIdWorker.nextId("order");
//        VoucherOrder voucherOrder = new VoucherOrder();
//        voucherOrder.setId(orderId);
//        voucherOrder.setUserId(userId);
//        voucherOrder.setVoucherId(voucherId);
//        //将订单信息加入阻塞队列
//        orderTasks.add(voucherOrder);
//        //获取代理对象
//        proxy = (IVoucherOrderService) AopContext.currentProxy();
//        //3.返回订单id
//        return Result.ok(orderId);
//    }
//    @Override
//    public Result seckillVoucher(Long voucherId) {
//        //1.查询优惠券信息
//        SeckillVoucher byId = seckillVoucherService.getById(voucherId);
//        //2.判断优惠券是否开放以及是否结束
//        if (byId.getBeginTime().isAfter(LocalDateTime.now())
//                || byId.getEndTime().isBefore(LocalDateTime.now())) {
//            return Result.fail("优惠券尚未开始或已经结束");
//        }
//        //3.判断库存是否充足
//        if (byId.getStock() < 1) {
//            return Result.fail("优惠券已经售完");
//        }
//        Long userId = UserHolder.getUser().getId();
//        //创建锁对象
//        String name = "lock:order:" + userId;
////        SimpleRedisLock simpleRedisLock = new SimpleRedisLock(name, stringRedisTemplate);
//        RLock lock = redissonClient.getLock(name);
//        //获取锁
//        boolean b = lock.tryLock();
//        //判断获取锁是否成功
//        if (!b) {
//            //获取锁失败，直接返回失败或者重试
//            return Result.fail("不能重复下单");
//        }
//        try {
//            //获取代理对象（事务）
//            IVoucherOrderService proxy = (IVoucherOrderService) AopContext.currentProxy();
//            return proxy.createVoucherOrder(voucherId); //先提交事务
//        } finally {
//            lock.unlock();
//        }
//
//    }

    @Transactional // 事务注解
    public void createVoucherOrder(VoucherOrder voucherOrder) {
        //一人一单的判断
        Long userId = voucherOrder.getUserId();
        int count = query().eq("user_id", userId).eq("voucher_id", voucherOrder.getVoucherId()).count();
        if (count > 0) {
            log.info("一人一单");
            return;
        }
        //4.扣减优惠券库存
        boolean voucherId1 = seckillVoucherService.update().setSql("stock=stock-1")
                .eq("voucher_id", voucherOrder.getVoucherId()).gt("stock", 0).update();
        if (!voucherId1) {
            log.info("库存不足");
            return;
        }
        save(voucherOrder);
    }
}
